Inscribed Circle-located inside the triangle and just touches its three sides
external image incircle.jpg


Circumscribed Circle- located outside the triangle and touches all three vertices.

Altitude: a perpendicular line segment from a vertex of a triangle to the line containing the opposite side.

Median: a line segment from a vertex to the midpoint of the opposite side.
external image avg_median.gif Example of Median
Rotation: When the circle moves in a complete 360 degrees
Midpoint: the point in a segment that divides it into two congruent segments.external image midpoint.jpg